I. Field of the Invention
This invention relates to a deadbolt latch mechanism for a door and, in particular, to a deadbolt latch which can be selectively triggered to be self-locking upon closing the door eliminating independently locking the deadbolt.
II. Description of the Prior Art
Deadbolt locks are widely used, particularly on residential doors, to securely prevent unauthorized entry. The configuration of the deadbolt deters tampering to provide secure latching. Typically, deadbolt latches require a key to be opened from the outside and either a key or a finger lever to be opened from the inside. As a result, the door must be closed and the key utilized to lock the deadbolt. Because of the inconvenience of loading the proper key, many users forego locking the deadbolt unless they will be away from home for extended periods of time.
Deadbolt latches have been developed which allow the user to lock the deadbolt without requiring the use of a key but prevents unlocking except in the conventional manner. In one prior known deadbolt, the bolt is latched using a secondary lever which controls extension of the bolt. Other prior deadbolt latches involve preloading the bolt through rotation of the turn lever beyond its normal position such that upon closing the door the bolt is released into the striker plate. Because of the complexity of the prior self-locking mechanisms, a great deal of additional mechanical structure is incorporated substantially increasing manufacturing costs. Moreover, it is desirable to conventionalize door locks so that they can be interchanged without concern. Modern latches are provided with well known mechanisms. The prior known self-locking deadbolt latches vary the configuration.